Method and apparatus for the production of music



Dec. 17, 1940. c. T. JACOBS 2,224,965

METHOD AND APPARATUS FOR THE PRODUCTION OF MUSIC Original F iled March 17, 1957 W Ar1f? arm a 57 l-Iil m: 6? ma a a a 66 M 5:

IN VEN TOR:-

Patented Dec. 17, 1940 UNlTED STATES PATENT OFFICE METHOD AND APPARATUS FORQTHE PRODUCTION OF MUSIC Application March 17,1937, Serial No. 131,398 Renewed November 1, 1939 ;19 Claims. (01. "s r-1.14)

This invention relates to the production of music, and more particularly to the control of that production. The invention has especial, though not in all aspects limitative, reference to that production by mechanico-electro-acoustic means-e. g., by some form of mechanical system arranged and operated to give rise to electric oscillations which, for example after amplification to any volume level desired, are translated into sound to create the output tones of the instrument.

Broadly it is an object of my invention to provide improved control for the output tones of a musical instrument.

It is an object to relate a plurality of controls in novel and useful manners.

It is an object to relate, in novel and useful manner, other controls with the control over output volume.

20 It is an object to relate mutually, in novel and useful manners, controls over qualitative characteristics of the output tones.

such a manner that they m' be readily adapted 25 to each of the variety of con itions and musical requirements which may arise from time to time in the use of the musical instrument.

It is an object to reduce thecomplication of an effective group of controls for a musical in- 30 strument.

It is an object to increase the useful flexibility of an instrument in respect of tone production.

It is an object to provide an improved arrangement of an instrument whose operation involves 35 the mixing together of a plurality of series of oscillations.

In the use of instruments of the damped tone type, a tone damping or decrement which is musically very pleasing at one volume level is fre- 40 quently found to be musically quite objectionable at another; andit is an object of my invention to provide means and methods for obtaining useful and pleasing tone decrements at all times in such an instrument.

It is an object to effect lkhserelationships in V 45 A specific object is the provision of a simple control whereby organ-like, piano-like or highlydamped tones may be obtained at will from a musical instrument.

A general object is the provision of a gener- 50 ally improved musical instrument.

Other and allied objects will more fully appear from the following description and the appended claims.

In the description reference is had to the ac- 55 companying drawing, of which the single figure is a view, partly crosssectional 'but principally schematic, of a musical instrument wherein my invention has been embodied.

The figure illustrates an embodiment of my invention, applied for example to a piano oper- 6 ating by mechanico-electro-acoustic translation.

In this figure will be seen th'erear portion lb of the metallic plate or frame of the instrument; the capo la forming a more forward portion of that frame; and a bridge 2 slightly forward of m the rear plate portion lb and vibratilly supported on wooden or other vibratile means, such as vibratile ribs 3. Stretched under tension from still more forward plate portions, under capo la and over the bridge 2 to a hitch pin 5 on plate portion lb, is seen a tuned string 4; and it will be understood that a plurality of such strings will be employed, at least one tuned to each different note in the scale, which plurality I have indicated by showing the rear portion of another string 4a engaging the hitch pin 5a. The strings may be maintained electrically insulated from eachother and from conductive portions such as the frame, accordingly each hitch pin may be set in an insulating bushing in the frame, such as the bushings 6 and Set for the two illustrated pins, and a strip I of insulation may be provided on the bearing surface of the capo la. While for vibrating each string no limitation to any particular means is contemplated in the broader aspects of my invention, I have illustrated for the string 4 a hammer 8, actuated by the pivoted key' 9 through the action ID to strike the string. There has also been illustrated a damper ll normally resting on thestring but coupled through the damper-lifting rod Ila to the pivoted lever l2; the rear end of the key 9 is arranged to lift the lever l2 and damper ll when the key is depressed at the front, as will be understood. For simultaneously lifting all dampers from their 40 strings I have schematically illustrated the pedal l3, pivoted, and coupled by pedal rod l3a. to a bar l4 passing under all levers l2. The string vibrating and damping means so illustrated will be recognized as those of the conventional piano.

While the broader aspects of my invention are not specific to any one type of mechanico-electrlc translating means, I have particularly illustrated such means of the capacitive, or electrostatic, type, which is basically provided by an electrode in slight spaced relationship to the strings. Following the teachings of prior Patents No. 1,906,- 607 to myself and No. 1,915,859 to myself and Miessner, I have shownjust below the strings at different longitudinal positions therealong a plurality of such electrodes, l5 and I8, each preferably in the form of a conductive strip of small cross-section and secured to the tops of narrow insulating strips [1 and I 8 respectively. While the insulating strips may be supported in any convenient manner, I have preferred to support them to the vibratile system composed of bridge 2 and ribs 3, according to the teachings of Pat out No. 1,912,293 to Miessner; and insulating strip l8 has been shown so supported, through the medium of block or clamp l9.

To render the conductive strips 15 and 58 active as translating devices, I may provide each with a connection to ground (1. e., to some reference potential, hereinafter often conveniently referred to) through respective leads 2| and 22 and respective resistors 23 and 24 each of high value; and I may provide means, hereinafter more particularly described, which at least at times establish the string at a direct potential difference from ground. These last mentioned means polarize each of the two small capacities between string and the respective conductive strips; and vibration of string portions respectively opposite the two strips, varying these respective capacities, cause respectively corresponding oscillatory variations of the minute charges in and voltages across those respective capacities, and hence respectively corresponding oscillatory voltages across the respective resistors 23 and 24. These oscillatory voltages accordingly are two series of oscillations, each representing the vibration or a different portion of the same string (or strings), and hence of similar fundamental frequency but of different harmonic structure. While this'description has been set forth with respect to the illustrated two translating means and two series of oscillations, it will of course be understood that no limitation to this particular number is intended.

As taught in the prior patent to me abovementioned, I may combine the several series of oscillations in controllable mutual amplitud and phase relationships, thereby creating composite oscillations of harmonic structure controlled according to particular partial components (as distinguished from the usually itself less effective control according to absolute frequency which is performed by simple frequency-discriminating electrical circuits). While this combination 0! the several series of oscillations may be effected before any amplification thereof or on the other hand after full amplification and translation thereof into respective series of acoustic oscillations, I have illustrated it as performed after some amplification of each series. Accordingly the two resistors have been shown coupled to the grids of the respective repeater or amplifying tubes 25 and 26 through the respective condensers 21 and 28 and the respective grid leaks 29 and 30. The cathodes of these tubes may be connected together and through icy-passed bias resistor 3| to ground, and a common battery or other highpotential current source 32 may furnish plate current for the two tubes. In the respective output circuits of the tubes may be connected the respective transformers 33 and 34; and across the secondaries of these transformers may be con nected the respective potentiometers 35 and 36, provided for example with the respective fixed center-taps 35c and 360, and with the respective fully movable contacts 35a and 36a. A series circuit may be formed of that portion of potentiometer 35 which may lie between 35a and 330; of. that portion of potentiometer 36 which may lie between 36a and 360; and of the input of amplifier 31, to which in cascade may be connected the potentiometer or main volume control 38, further amplifier 39, and loudspeaker orother electro-acoustic translating device 40. Grounded electrostatic shielding schematically shown as 20 may be disposed about sensitive portions such as .15, I6, and those numbered 2| thru 30.

The manner of functioning of the combining arrangements so described, to combine the series of oscillations in controlled mutual amplitude and phase relationships, has been 'fully set forth in the prior patent to me abovementioned, and need not be here repeated. And it Wil1 be obvious that the combined oscillations are amplified by the two amplifiers 31 and 39, may be controlled in respect of amplitude by the volume control 38, and are translated into output tones by the electroacoustic translating device 40.

The movable contact 38a of the potentiometer or volume control 38 is shown mechanically (but insulatedly as to electric current) connected to a foot swell pedal or the like designated as 43, for

vexample centrally pivoted as at 44 to some rigid member 45; schematically this connection has been shown as made through the linkage 4i, pivotally connected as at 42 to the pedal extremity.

One of the features of my invention deals with the variation of output tone harmonic structure jointly with the primary control of volume; and whil I intend no limitation of this feature to any particular means, I have particularly shown, for effecting this variation in the manner defined, a simple linking of the movable contact 36a of the above described potentiometer 36 with the movable contact 38a of the volume control 38. A variation of harmonic structure jointly with volume is recognized as frequently very useful musically and acoustically, and in its broadest aspect is not new. Insofar as I am aware, however, harmonic control linking with a primary volume control has been limited to harmonic controls opcrating according to absolute frequency, for ex ample through the action of simple frequencydiscriminating electrical circuits. It will be obvious, however, that according to the present illustration I have linked with the primary volume control a harmonic structure control operating in accordance with particular partial components of each tone.

It is true that in Patent No. 1,906,607 to me, abovementioned', I showed (Fig. 4) an interlinking of an amplitude control (I03) with harmonic structure controls operating in this manner; but, specifically, this amplitude control was not a primary volume control, but rather a secondary compensating means for amplitude inequalities occasioned by the harmonic controls-and the present use, both as already and as hereinafter appearing, represents a concept possessing a large measure of utility thereover.

Before describing'in detail the linking of 36a to 3812, I may call attention to the fact that it with an extremity of this rod 46, as at 43, so that the rod rocks about its pivot with pedal manipulation and hence with volume control action. At an intermediate position on the rod 45 will be seen a collar 50, which is slldable along the rod but securable at any point therealong by a setscrew provided with a head in the form of a hand-knob 52. Pivotally secured to this collar, as at 53, is a rod 54 extending in the direction of the potentiometer 35; and about this rod 54 is provided a slidable collar-scremknob assembly 55-56-51, for exampl like 50-5I-52. The potentiometer contact 36a is mechanically (but insulatedly as to electric current) connected with the collar 55; and when it is desired to link this contact with the volume control contact 38a, the knob 51 is manipulated to secure the collar 55 to the rod 54-it being understood that when the collar is not so secured the rod 54 may slide freely within the collar 55 as the pedal is manipulated, the collar remaining stationary in a position determined by that to which the contact 36a may have been adjusted manually and independently of the volume control.

When the collar 55 is secured to the rod 54, the degree relationship between the harmonic structure variation and the volume variation, effected jointly as by the pedal 43, may be regulated by sliding the collar 50 along rod 45 and locking it in place by knob 52 at the chosen position; this, varying the leverage about the pivot 41, varies the relationship between therespective distances of movement of the contacts 360. and 38a. The

range relationship between harmonic structure and volume variations-e. g.,,the relationship between the mean of the'one movement range and that of the other-may be adjusted as desired by appropriately fixing the position of the collar 55 longitudinally along the rod 54. The direction relationship between the two variations may be regulated either-by choosing the appropriate half of the potentiometer 36 for the contact 35a to operate over or (particularly ifit be desired to operate the contact 36a. back and forth over the center-tap 36c by volume control manipulation) by an equivalent choice of direction of displacement of the contact 35a of potentiometer 35 from the center-tap 35c of'that potentiometer.

' The effects which may be produced by this inter-linkage of harmonic structure control with volume control are so many and varied that it is impossible to detail them; a purely typical use may be the addition to the oscillations translated by strip l5, say as volume is increased, of increasing amounts of oscillations translated by strip ii. In such a case the latter oscillations, being translated from nearer the string extremity and therefore being predominate in higher partial components, will tend to brighten the. tone with increasing volume (very frequently a desirable musical effect); and if the relative displacements of the two variable contacts 35a and 36a from their respectively associated center-' taps be at the same time such asto result in bucking of the lowest partials (say the fundamental, second and third), such brightening will be especially enhanced. But no limitation of use to the production of any specific effect is intended, the purpose being rather to show broadly the inter-linkage with volume control of tone control on the basis of particular par- I tials.

Another tonal characteristic of which a control, according to my invention, may be linked with the volume control (or linked with the tone to Miessner.

control or linked with both volume and tone controls) is the tonal envelope, or amplitude-totime relationship. One important characteristic of the tone envelope, particularly in the case of momentarilyexcited tones such as those from a vibrator struck or plucked, is the rate of damping of the tone; so I may provide means for controlling this damping rate and suitably interlink those means with the other control means, or any of them, above described.

First, as a non-limitative example of damping and damping control means, I have shown and will describe briefly a system similar to that iilustrated and described in Patent No. 2,033,440 This involves the securing to the vibratile system, composed of bridge 2 and ribs 3 and of course vibrationally coupled with the strings, of a heavy, electrically conductive strip 60, as by means of brackets 6i holding the strip 60 in a vertical position underneath the bridge.

At as many points as may be desired along the strip 60 there may be associated therewith means for passing therethrough a heavy magnetic field; and I have illustrated such a means as a heavy electromagnet 62, rigidly mounted (as by bracket 63 to plate portion lb) and having poles 64 in mutually opposed relationship on opposite sides of and close to the strip 60. To the winding portion (65) of such electromagnetic means I have shown electrically connected the conductors 66 and 51, of which the former may connect to one terminal of a battery or other heavy cur-- rent source 68. The other conductor, 61, has been shown connected through a switch 69 to a resistance 10 (the switch permitting a connection of the conductor to either,-or neither, extremity of the resistance); and a variable contact Illa on this resistance may be connected, preferably through a potential-regulating switch I I to another point or points in the source-58.

The operation of this damping means, as more fully set out in the patent to Miessner last above mentioned, depends on the induction of currents .in a conductor upon vibration thereof in a magnetic field. Obviously the string vibration is attended by a principally vertical vibration of the bridge and hence of the strip 60, and currents are induced in the strip, their energy heating the strip and being thereby dissipated. This energy is abstracted immediately from the vibratile system 23, but ultimately from the strings; and this abstraction or loss from the strings increases their rates of damping. Control of the field strength, exerted by any control over current through 65, controls the energy loss and hence the string damping; since the output tones are translated from the strings, their damping is correspondingly controlled.

I have provided in the resistance and variable contact Ill-10a a means of controlling the current through 65 and therefore the tone damping; and according to my invention the contact 10a is mechanically inter-linked with other controls, as through the intermediary of rod 46. So on that rod may be provided a second collar-screwknob assembly 12-l3- -'l4, and there may be pivotally securedto collar 12, as at 15, the rod 16 extending in the direction of the resistance In; a co1lar-screw-knob assembly 11-1-8-49 may be provided on the rod 16, and the contact Illa is mechanically (but insulatedly as' to electric current) connected with the collar 11.

In similar manner to that above described for movement of the contact 36a with movement of the rod 46, pedal 43 and contact 380., the contact 70a will be moved, varying damping simultaneously with volume (unless collar 1! be loosened on rod 16 by knob 19). Adjustment of the degree relationship between damping and volume variations, or between movements of 10a and 38a, will be fully regulated by choice of position of collar 12 on rod 46 (it being obvious that a separate branch of that rod may be employed for collar 12 should desired movement thereof conflict with collar 50). Adjustment of the range relationships between damping and volume variations' will be regulated by choice of position of collar ll on rod 16 (both degree and rangerelationship adjustments being augmented if desired by adjustment of the switch 7!). And adjustment of the direction relationship will be effected by switch 69, which at will will render either extremity of resistance 10 the active one, or eliminate the damping altogether.

While obviously I do not intend a limitation of broader aspects to either direction relationship between volume and damping variations, I do point out as a more specific aspect the particular use of damping increase with volume increase; this I have found of tremendous musical value. For example in a piano, the elimination of the soundboard and hence of direct mechanico-acoustic energy losses from the strings results, if uncounteracted, in a reduction of damping rate; this, long sought in the conventional piano, is a very pleasing efiect at'low and even at medium volumes, but at high volumes is frequently very objectionable-doubtless because of the amplitude dependence of dissonances (e. g., beats) on mutual products, rather than first powers, of the amplitudes giving rise to them, together with the sharp increase in noticeability of dlssonances with low damping rates. Obviously my invention provides a complete solution for this difllcultyand this is only exemplary; similar effects are quite generic to all instruments producing damped tones, and the present aspect of my invention is of great utility with them all.

When combined damping and volume control is employed, a simultaneous control of harmonic structure may be employed or not, as desired and for example according to the adjustment of knob 51!. There is alternatively possible, however, the inter-linking of damping and harmonic structure controls without the simultaneous control of volume; this is effected through the intermediary of rod 46, but with that rod divorced of operative connection with the pedal 43. (To make possible such divorcement I have shown the top portion of the linkage 4| in the form of a rod Ma, and the abovementloned connection thereof with the pivot 49 extremity of rod 46 as made through a collar-screw-knob assembly -8l--82 secured to that pivot and engageable and disengageable at will on the rod Ma.) The joint harmonic structure and damping controlresponsive to manual adjustment of either 360 or 10a, and obviously fully controllable in degree, range and direction relationships-provides some highly interesting musical effects very diflicult of achievement without the aid which their unicontrolling provides.

It will be understood that in the case of the inter-linking of harmonic structure control with any control other than volume, or with volume and still other control, my invention contemplates harmonic structure control quite broadly, and not necessarily limited to control in accordance with particular partial components or the like.

While hereinabove I have shown a damping control as illustrative of tone envelope control in linking of the latter to other controls, I intend no limitation thereto; my invention, still not'limitatively, extends to other forms of envelope con- 'trol, such for example as the electrical ones shown and described in Patents Nos. 1,915,859, 1,915,860 and 2,071,649, each to Miessner and myself. By way of illustration herein 1 have shown, incorporated in the instrument of Figure 1, an electrical envelope control closely following the teachings of the last of these three patents, and an association of the controlling or varying elements thereof with other controls of the present instrument. This particular envelope control is one which operates by varying the efficiency of the translation-e. g., of the mechanico-electric translation-of each tone in predetermined relationship to the manipulation of the playing members governing the production of that tonee. g., key in and damper pedal l3. Still more specifically, it may operate by controlling the polarizing voltage supplies to the individual strings, which it will be recalled were only generally mentioned hereinabove.

Thus each string, through the medium for example of its associated hitch pin such as 5, may receive its polarizing voltage through a respective resistance-condenser filter, such as has been illustrated as 83 for the string 4 and as 83a for the string 4a. Filter 83 may for example comprise the series resistances 84 and 86, and the capacities 85 and 87 shunted from the stringward extremities of the respective resistances to ground; filter 83a, for an adjacent note, may be correspondingly formed (the letter a having I been added to each designating numeral), and so on. The voltage input to each filter is obtained from the polee. g., 89, and 89a, etc.of a respective single-pole double-throw switch 88, 88a etc., of all of which switches the lower-throw contacts (e. g., 90, 90a) are connected to a common conductor 94 and the upper-throw contacts (e. g., 9i, Bid) to a common conductor 95. The pole of each switch is mechanically connected by a respective rod-e. g., 92, 92a-to the damper (such as H) for the respective note; when that damper rests on its string the pole of its switch will be in lower-throw position, and when that damper is fully raised (as by depression of the respective playing key such as it) that pole will be in upper-throw position. (Preferably the pedal l3 will raise all the dampers only so far as to place all the switch poles in an intermediate position between but not touching either of their upperand lower-throw contacts.) The conductors 94 and 95 are connected respectively to the variable contacts 96a and 91a of two respective potentiometers 96 and 91, across each of which is connected the battery or other high potential source 98 of polarizing voltage, of which source one terminalmay be grounded.

Neglecting for the moment certain novel features in the illustration of the system 95-91-48 5 which will hereinafter be described, it will be seen that each of the conductors 94 and 95 may, by its associated variable contact 96a or 97a, be established at ground potential, at full source 98 potential difference from ground, or at any poten- 7i tial intermediate these two. In view of the normal lower-throw position of the switch poles 89, 89a, etc, contact 96a regulates the normal polarizing voltage on the strings; conversely contact 91a. regulates the polarizing voltage which will 7'.

be acquired by each string upon depression of its associated key--or, in convenient terms, the operating polarizing voltage. So upon depression of any key the polarizing voltage of its associated string will change from the normal to the operating voltage; since the translation efllciency depends directly on the polarizing voltage, it will be correspondingly changed. Upon key release the spring polarizing voltage and translation efficiency will conversely return from the operating to the normal value (unless pedal l3 then be in a depressed position to prevent full return of any switch poles to their lower-throw positions, in which event the string voltage and translation efiiciency returns to normal will be postponed until pedal release). Each of these changes will occur at a finite, rather than an infinitely rapid, rate, which will be dependent on the choice of values for the resistance-condenser filters 83, 83a, etc.; typically these changes may be substantially completed in some fraction of a second, though no particular limitation in this respect is intended.

If contacts 96a and 91a. be adjusted for mutually similar normal and operating potentials, no potential variations take place and the translations occur at a constant efficiency; a tone is produced with envelope corresponding to the string vibration envelope. If, however, contact 96a be adjusted for a ground normal potential and contact 91a for a finite operating potential, translation is absent at theinstant of key depression but builds up to a finite value through a short immediately succeeding time interval, producing gradual or organ-like tone attack or increment and so modifying the tone envelope from that of the string vibration. And, conversely, if contact 96a be adjusted for a finite normal potential and contact 910. for a finite but much lower operating potential, the translation is normal at the instant of key depression and tone beginning, but falls during a succeeding time interval to a much lower valueproducing a decrement or eifective damping of the tone, particularly in its early portion. For-further discussion of these and other elfects made possible by the adjustment of such two contacts, reference may be had to the last of the three patents last abovementioned A feature of the present illustration of this system is the unicontrolling of the two contacts 960. and 91a. They have been shown linked mechanically (but insulatedly as to electric current) through the tiemeans '99; and at the same time the electrical connections which parallel the two potentiometers 96 and 91 are criss-crossed" or otherwise arranged so that while the contacts may travel in the same direction mechanically, they travel in opposite directions electrically (i. e.,

in respect of potential). Obviously by this ar-.

rangement it is possible with a single manipulation progressively to modify the envelope, nothat the tone may be varied from one of gradual attack or increment, through one of normal string characteristics (e. g., pianistic), to one of high decrement or efiective damping as above dis-.

cussed. The resistance elements of the potentiometers 96 and 91 may be either complementarily tapered or of non-tapered form.

I have shown the envelope control so described inter-linked for simultaneous manipulation with the heretofore described volume control, har- ..monic structure control, and damping control (the latter being the other specifically illustrated envelope control); and if desired with any two or with any one of these (the appropriate ones of the collars 55, TI and 80 being loosened to eliminate the linking of, those not desired). This is simply accomplished by providing on the.

of the other controls, the degree relationship of this control may be adjusted by choice of position of collar I00 on rod 46, and the range relationship by choice of position of collar I05 on rod I08. For adjusting the direction relationship to any one or more of the other controls, I have provided, in the connections from the two potentiometers 9691 to the source 98, the polarity-reversing switch llD--by which the ground and high-potential potentiometer extremities may be reversed, simultaneously for both potentiometers.

The remarks made above with respect to the inter-linking of damping control with harmonic control, volume control, and volume and harmonic control, of course apply also to the justdescribed envelope control, in view of its control of an efl'ective damping function; particular but not limitative attention is directed to its interlinking with volume control to increase effective damping rate with volume, for reasons specially above set forth. The just-described control being wider in its scope than the. damping control, however, will in general provide a further variety of effects when inter-linked in any of the mentioned ways. And although it embraces an effective damping control function, its simultaneous inter-linked use with the damping control, with or without other controls, is also contemplated by my invention; such inter-linked use may be made, for example, to produce at will either a gradually beginning and rapidly decaying tone fluences, in contrast to the relatively rapid-rate influence of the envelopeor attack'control (e. g., contacts 96a9'ld), which latter will be understood (and may be seen from the typical component values cited in the patents to Miessner et al. abovementioned) to complete its change in an interval of the order of a fraction of a second. Therefore the mere joint use of these two controls, without their mutual interlinking (or with either one linked with one or more of the other controls, as above described), aifords an especially complete and integral kind of envelope control-the tone starting essentially under the control of the envelopeor attack-control means but relatively quickly shifting to come under the control of the damping means, and the two control means jointly determining the tone envelope during the brief interval of the shift.

I call attention to the fact that all of the tone characteristics over which I have shown control, with the exception only of volume, are qualitative characteristics, and are so referred to in some of the claims. In certain of the claims I have referred to the production or control of groups of tones, by which I intend to include musical passages, for example with their chords and sequences; and I may refer to the general control of the volume of such a passage, as distinguished from individual note amplitude control, as mass volume or amplitude control.

Further, I have referred to envelope control as control of the envelope shape, by which I of course mean toexclude changes of a tone envelope which are mutually proportionate at every time-representing point in the envelope-i. e., which actually are only quantitative or volume changes of the envelope.

Finally, it will be understood that while I have disclosed my invention'in terms of a particular embodiment thereof, I intend no limitations by virtue of the details of that embodiment, which are necessarily illustrative rather than comprehensive; rather in the appended claims I undertake to express the scope of my invention broadly, limited only by the state of the art.

I claim:

1. A musical instrument having mechanicoelectro-acoustic means for producing output tones, and two control means associated therewith for varying respectively the envelope shape and the volume of said tones, one of said control means being connected with and operated by the other.

2. A musical instrument having mechanicoelectro-acoustic means for producing output tones, and two control means associated therewith for varying respectively the damping and the volume of said tones, one of said control means being connected with and operated by the other.

3. A musical instrument having mechanicoelectro-acoustic means for producing output tones, and two control means associated therewith for varying respectively two mutually distinct qualitative characteristics of said tones, one of said control means being connected with and operated by the other.

4. A musical instrument having mechanicoelectro-acoustic means for producing output tones, and two control means associated there with for varying respectively the envelope shape and the harmonic structure of said tones, one of said control means being connected with and operated by the other.

5. A musical instrument having mechanicoelectro-acoustic means for producing output tones, and two control means associated therewith for varying respectively the initial increment and the later decrement of said tones, one of said control means being connected with and operated by the other.

6. A musical instrument having a plurality of control means for varying respectively the envelope shape and the volume of its output tones, means interconnecting said control means for joint manipulation thereof in predetermined mutual relationship, and adjustable means included in said interconnecting means for variously predetermining said relationship.

'7. A musical instrument having a plurality of control means for varying respectively two mutually distinct qualitative characteristics of its output tones, means interconnecting said control means for joint manipulation thereof in predetermined mutual relationship, and adjustable means included in said interconnecting means for variously predetermining said relationship.

' 8. A musical instrument having means for controlling the volume of its output tones andmeans for controlling the envelope shape of said tones, said two control means being mechanically coupled to each other for joint manipulation in predetermined relationship.

9. A musical instrument having means for controlling the volume of its output tones and means for controlling the damping of said tones, said two control means being mechanically coupled to each other for joint manipulation in predetermined relationship.

10. A musical instrument having means for controlling the envelope shape of its output tones and means for controlling the harmonic structure of said tones, 'said two control means being mechanically coupled to each other for joint manipulation in predetermined relationship.

11. A musical instrument having means for controlling the initial increment of its output tones and means for controlling the later decrement of said tones, said two control means being mechanically coupled to each other for joint manipulation in predetermined relationship.

12. In musical tone production from tonerepresenting electric oscillations, the method of control of a group of tones, which includes jointly controlling, in predetermined relationship, both the mass volume and the individual envelope shapes of the oscillations severally representing said tones.

13. In musical tone production from tonerepresenting electric oscillations, the method of control of a group of damped tones, which in- ,cludes jointly increasing and decreasing both the mass volume and the individual decrements of the oscillations severally representing said tones.

14. In musical tone production from tonerepresenting electric oscillations, the method of control of a group of tones, which includes jointly controlling, in predetermined relationship, both the envelope shapes and the harmonic structures of the oscillations severally representing said tones.

15. A musical instrument having means for producing a plurality of series of wcillations, means for mixing together said series of oscillations, primary volume control means for varying the amplitude of the mixed oscillations, and means connected with and operated by said volume control means for varying said mixing.

16. In a musical instrument having means for producing output tones: control means selectively adjustable to invest said tones with initial increment and initial decrement, including a pair of electrical control devices; and means, interconnecting said devices, for rendering the adjustment of said control means-progressive from an initial increment adjustment through a dormant adjustment to an initial decrement adjustment and vice versa.

17. A musical instrument having mechanicoelectro-acoustic means for producing output tones, primary control means for controlling the volume of said tones, and control means, connected with and operated by said primary control means, for varying the harmonic structure of said tones according to particular partials thereof.

18. In a musical instrument having means for generating tone-representing trains of electric oscillations and means for translating output tones from said oscillation trains: the combination of envelope-control means connected with said generating means and operable to influence both the initial portion and succeeding portions of the tone envelope at a relatively slow rate;

and other adjustable envelope-control means electrically connected with said generating means and operable to influence only said initial portion of the tone envelope but at a relatively rapid rate, whereby the envelope of each tone starts essentially under the control of said secondmentioned control means but relatively quickly shifts to come essentially under the control of said first-mentioned control means.

19 In a musical instrument of the type wherein output tones are translated from trains of electric oscillations: the combination 0! tone decrement control means, electrical tone-attack control means, and key-operated means, with which both of said control means are associated, for producing tone-representing trains of oscillations responsive to both said control means, whereby both graduality and abruptness of both attack and decrement of said tones are selectively available in any of their several combinations.v

CHARLES T. JACOBS. 

